Steel retainer



Patented June 2, 1931' uNir osT-A rns PATENT OFFICE FRED M. SLATER, OF EASTON, PENNSYLVANIA, ASSIGLIOR TO INGERSOLL-RAND COM- PANY, OF JERSEY CITY, NEH) JERSEY, A CQRPORATION OF NEW JERSEY s'rnnr. RETAINER Application filed October is, 1929. Serial 1%. 398,946.

This invention relates to rock drills, but more particularly to steel retainers adapted to be attached to rock drills of the type in which the hammer piston reciprocates independently of the drill steel.

The objects of the invention are to enable the use of a heavy and rigid retaining element and to lock the retaining element conveniently in the retaining position without nocessitating undue friction between it and the locking means when looking the said retaining element from one limiting position to another.

Other objects will be in part obvious and in part pointed out hereinafter.

In the drawings illustrating the invention and in which similar reference characters refer to similar parts,

Figure 1 is a side elevation in section of a portion of a rock drill having the invention applied thereto and Figure 2 is afront elevation, partly in section, of the front end of a rock drill and the retainer.

Referring to the drawings, A represents the cylinder of a drill to which is secured a front head B by means of side bolts C. A front cylinder washer D is interposed be tween the cylinder A and the front head B to hold these elements in coaxial relationship with each other and has a bore E through which extends slidably the extension F of a hammer piston G reciprocable in the cylinder A.

The front head B acts as a housing for chuck mechanism designated generally by H for guiding a working implement J against which the hammer piston G is adapted to strike. The working implement J may be a drill steel and of polygonal form to engage a corresponding bore K in the chuck H into which the shank L of the drill steel J extends.

At the juncture of the body portion of the drill steel and the shank L is a collar 0 which, when the drill steel J is fully retracted, abuts the front end of the chuck H to limit the distance which the shank L may extend into the front head.

On one end of the front head B is an enlargement P in which is formed a transverse aperture Q of oblong shape. Preferably the ends R of the apertures Q, are of semi-circular form and the sides S. of the apertures are tangent to the semi-circularv ends R.

Means are provided for limiting the degree of reciprocatory movement of the drill steel J with respect to the front head B and to insure the retention of the drill steel in the front head. This means comprises a yoke T which partly encircles the drill steel J forwardly of the collar 0 and side arms U integral with the yoke T and-extending rearwardly along the sides of the enlargement P. In the rearward or free ends of the side arms U are holes V to receive the ends of a shaft W which lie in the uppermost portion of the aperture Q to form a pivot for the yoke T.

The retaining means so far described are inmost respects substantially like that disclosed in United States Patent No. 1,671,133 for steel retainer granted to F. M. Slater May 29, 1928. The present invention differs, how ever, from the aforesaid patent in the respect that the side arms U, instead of being flexible, are of such cross sectional area that they are substantially rigid. This is desirable since it enables'the retaining yoke to be sufficiently strong to withstand the severe usage and heavy blows to which it is subjected. The inner surfaces of the side arms may therefore at all times lie flush against the ends of the enlargement P.

In accordance with the present invention, means are provided for securely locking the yoke T in the retaining position. This means comprises a casing X disposed in the aperture Q beneath the shaft W and having a bore Y therein to accommodate plungers Z which are disposed in opposite ends of the bore and preferably have their outer ends rounded as at b to engage sockets or depressions c in the inner surfaces .of the side arms U. The plungers Z may be of suitable length to insure ample bearing surface between them and the bore Y and are so spaced with respect to each other as to permit the insertion therebetween of a spring d which acts against both plungers to press them outwardly in the direction of the side arms U.

In order to cushion the yoke T a rubber buffer 6 is disposed in the bottom of the aperture Q to form a seat for the casing X. The entire arrangement is such that in the event I that the drill steel J is driven violently forward so that the collar 0 impacts against the yoke T the force of the blow will be transmitted through the casing X to the buffer eto cushion the movement of the yoke.

Any convenient means may be used for holding the shaft W, the casing X and the buffer 6 against endwise movement in the aperture Q. In the present instance a bolt f is disposed in a hole 9 which extends longiside arms U-of great rigidity may be employed for retaining the drill steel J in the front head. This is made possible by the use of the spring pressed plungers which permit the retainer to be readily rocked from one limiting position to the other without causing undue friction between these elements.

I claim:

1. In asteel retainer, comprising in combination with a front head and a collared drill steel, an enlargement on the front head having an aperture, a yoke for retaining the drill steel in the front head, side arms on the yoke, a shaft in the aperture forming a pivot for the yoke, a plurality of holding means reciprocable in the aperture, common actuating means acting against the holding means to press said holding means into engagement with the side arms for holding the yoke in the retaining position, and a rubber buffer in the aperture to cushion the yoke.

2. In a steel retainer, comprising in combination with a front head and a collared drill steel, an enlargement on the front head having an aperture, a yoke for retaining the drill steel in the front head, side arms on the yoke, a shaft in the aperture forming a pivot for the yoke, a rubber buffer in the aperture to cushion the yoke, a cage interposed between the shaft and the buffer and having a bore, and means reciprocable. in the cage to engage the side arms-for holding the yoke in the retaining position.

3. In a steel retainer, comprising in combination with a front head and a collared drill steel, an enlargement on the front head having an aperture, a yoke for retaining the drill steel in the front head, side arms on the yoke, a shaft in the aperture forming a' pivot for the yoke, a rubber buffer in the aperture to cushion the yoke, a cage interposed between specification.

FRED M. SLATER.

III 

